1. Field of the Invention
The present invention relates to a metal-oxide-semiconductor (MOS) transistor and, more specifically, to a complementary MOS (CMOS) transistor, such as for a power switch.
2. Description of the Related Art
MOS transistors and, more particularly, CMOS transistors are utlizied for a variety of applications, including power switches. In fact, one of the most fundamental factors of a power integrated circuit is a bridge circuit, in which pull-up and pull-down transistors selectively switch a load node in the opposite directions to each other. The related general structure is an H-bridge circuit where two points connected to the load are connected to a half-bridge circuit. The half-bridge circuit is used particularly in the control of a motor because the current is driven in either of the two opposite directions. Generally, a power integrated circuit includes an N-channel power field effect transistor (FET), for example a VDMOS device, in the driver circuit. Use is typically made of a MOS transistor, e.g., a complementary MOS transistor, for the power switch for the driver circuit of a power FET, especially a high-side driver.
MOS transistors, including CMOS transistors, preferably have a high breakdown voltage and resist parasitic operation. For example, the complementary MOS transistor used for the high-side driver must have a sufficiently high breakdown voltage and avoid parasitic operation to provide proper switching.